Mandarin plant leaves curling and wilting

I dug out a 4 years old mandarin plant from ground 2 weeks ago (someone gave me for free), then I trimmed and cut some roots before put it in a garden bed.
Found out the leaves are curling and wilting, wonder if I damaged the roots? Cut too much?
PS: it is spring here in Australia.

 

Now it shows signs of dying...leaves were curling, turned yellow, dropped and now looks like dying.